Coiled tubing drilling offers the advantages of reducing both time and costs associated with drilling operations. Reduced pipe handling time, pipe joint makeup time, and reduced leakage risks all attribute to the cost saving.
Although offering the above-mentioned advantages, there are instances where coiled tubing drilling has been unable to perform certain drilling operations and thus requires the assistance of a conventional rig. For example, there are instances where using coiled tubing to drill surface holes has proven difficult due to the lack of bit weight at the surface or shallow depths. When such circumstances arise, a separate and conventional rig is required to drill a surface hole, place surface casing, cement and then drill the vertical well portion. After drilling, a separate rig is brought in to run in the sectional and tubular production casing.
References such as U.S. Pat. Nos. 6,003,598 and 6,973,979 are directed to rigs aimed at performing all of the above described tasks from a single rig. These type of rigs, however, face obstacles in the US that arise from the inability to transport these large over weight units without falling outside of the “road legal” requirements set by the US Department of Transportation (DOT).
Accordingly, there exists a need for a coiled tubing rig that can easily be transported in the US while retaining its operational efficiency.